A motor vehicle generally has a number of closable and latching exterior aperture covers. The vehicle generally includes a hood to cover the engine and prevent dust and moisture from entering the engine compartment, as well as a lid for the trunk. In order to open the hood or access the trunk, the respective cover generally employs a hinge arrangement, spring assisted or otherwise, designed to assist an operator in lifting and securing one end of the cover in an open position. Typically, single pivot hinge arrangements are used in these applications. Single pivot arrangements, however, can be limited by their construction and/or packaging constraints of a vehicle body. Typically, when a cover equipped with a single pivot hinge is raised, the cover's front portion will rise, while the portion to the rear of the linkage will generally dive, i.e. drop below its starting position. In vehicles with tight packaging constraints, such hinge-imposed motion may result in the rear portion of the cover interfering with other portions of the vehicle body, which is undesirable.
A four-bar linkage hinge provides a solution for dealing with such space-restricted packages. The four-bar linkage hinge has two pivoting bars linking an upper bar which mounts to the cover and a lower bar which mounts to the vehicle body. In operation the four-bar linkage generates a compound motion of rotation and vertical translation. As generally configured for use with a vehicle hood the linkage's compound motion is disproportionate in favor of vertical translation. Such configuration is typically chosen to prevent the portion of the hood to the rear of the linkage from diving below its starting position and into the body structure when the hood is raised. With this type of articulation, however, an angled frontal impact force on the vehicle body may drive the hood rearward and transversely with respect to the vehicle centerline, thereby causing the rear portion of the hinge, and particularly the rear corner of the hood, to lift or move upwardly and translate toward the vehicle's passenger compartment.
It would be desirable to provide a four-bar linkage hinge that can open during regular operation, but whose rear portion would be restrained from lifting up and translating rearward when the linkage is subjected to a transverse deflection.